The technology now exists to digitize hundreds of contiguous high resolution fields of a microscope slide, merge them together into a gigabyte-sized file, and save the information in a highly compressed format. A web browser, by accessing these files, can nearly perfectly emulate a glass slide and microscope. Utilizing this technology, the first year of this project will result in development of a novel public domain Database of Human Microscopic Anatomy, consisting of a complete set of 151 high-resolution virtual microscopic slides of every adult human organ and tissue. This database will subsequently be enhanced by linking the 151 virtual microscopic slides to corresponding gross anatomic structures of the Visible Human data set and to gross color images of organs and tissues. In addition, provisions will be made for an on-line syllabus where concise gross, microscopic, and physiological correlations can be added to the database. In the second and third years of the project the technology and concepts developed in the first year will be extended to the related discipline of pathology, resulting in a public domain Database of Human Histopathology, consisting of approximately 300 virtual microscopic slides. These entirely novel databases will provide educators with a comprehensive set of peer-reviewed digitized microscopic slides, with accompanying gross images. Each database will be available to medical, dental and undergraduate schools via the Internet or removable media. The set of virtual microscopic slides in this database can be used via web browsers in academic courses as a virtual slide box, or as a source of images to develop computer-based educational programs. In addition, these databases will allow educators, who currently teach in expensive microscope laboratories, to maintain the pedagogic advantage of glass slides and microscopes, if their institution downsizes their microscope laboratories. The success of this project will be determined by its evaluation and implementation into the curricula at the University of Iowa and three collaborating institutions, and ultimately at academic institutions around the country.